XR, what are you talking about? Just because they use a 450cc single from a dirtbike doesn't mean its a conversion!
And those would smoke CRF-motards...at least on a road race track! And, as a former owner of a CRF450 motard, they are crap at high speed. I would not want to gear one for 120mph and see what it felt like. Even the Duc Hypermotard was too flighty for me.
As soon as Aprilia came out with the new v-twin 450/550 we all hoped they would put it in a RS250 chassis. That would be the perfect racer.
If these start coming out at reasonable prices I might get one to race next year. I never bought a GP bike because I didn't want to deal with top ends or jetting all the time.
But yes, as a street bike it is retarded!!!